Turnbuckle



Dec. 1, 1954 J, H, OOTH 2,696,397

TURNBUCKLE Filed July 20, 1950 design,

.,6 6, TURNBUCKLE Application July 20, 1950, Serial No. 174,871 1 Claim.(Cl. 28,7.60)

This. invention relates, to an improved type of turn buckle foradjustably attaching two connecting members.

More specifically, the invention relates to an improved turnbuckle ofgenerally tubular construction havingv an expanded turnbuckle barrel andwhich taining clamps on each end in. properlongitudinal position on thebarrel. The invention also includes the method of making the turnbucklebarrel.

According to this invention a generally tubular turnbuckle barrel, whichmay be formed by rolling a-blank of sheet metal into the desired tubularshape, isformed with a central portion of slightly larger diameter thanthe. end portions. The endportions are internally, threaded withright-hand threads wihin one end portion and left-hand threads withinthe other. Slots are. formed axially inwardly through the wall of thebarrel from each end thereof and extend almost to the central portion.Clamping rings are inserted over the ends of the barrel and have boltsextending across the slots in the barrel. When connecting members havebeen threadedly inserted into the internally threaded ends, the clampscan be tightened on the barrel ends serving to squeeze the ends of thebarrel tightly about the attached ends of the connecting members. Tabsare pressed out of the metal of the barrel at either side of eachclamping ring at points substantially diametrically opposite the slots,and these tabs serve to retain the clamps on the ends of the barrel evenwhen the clamps are loosened to permit rotation of the turnbuckle barrelabout the ends of the connecting members.

The turnbuckle of the present invention, having an increased diametercentral portion, has several distinct the conventional turnbuckle ofthis type.

barrel most likely to fail under a heavy load. By increasing thediameter of the unsupported central portion the section modulus isthereby increased and thus the tube is strengthened. In addition, due tothe increased inside diameter of this central portion, the internalthreads cut at the ends do not extend into the central portion, leavingit free from weakening notches which make for high stress concentrationsand consequent y failure under load. Furthermore, the turnbuckle needhave threaded sections as the minimum required threaded engagethe largercentral portion provides an unthreaded for adjustment between the endsof the connecting members. In the conventional in order to provide thenecessary adjustment length, the thread must be substantially longerthan the minimum required engagement.

an object of this invention to provide a nlarged diameter centralportion with increased section modulus and a smooth unthreaded innersurface in the central portion.

A further object of the invention is to provide a tu buckle barrel withan enlarged central portion with internally threaded end portions ofminimum required threaded lengths.

A further object of the invention is to provide a turnbuckle assemblyhaving clamping rings at either end and having tabs pressed outwardlyfrom the metal of the turnbuckle barrel on either side of each of theclamping portion of the United States Patent O 2,696,397 Patente D ,95

rings for retaining the clamping rings on barrel.

Another object of the invention is to provide a turn: buckle barrelhaving an enlarged central portion which maybe easily and, inexpensivelyformed by rolling a piece of flat metal sheet into the desired shape.

Still another object of the present invention is to pro-v vide a novelturnbuckle barrel of increased strength without necessitating asubstantial change in existing methods of manufacture and without usinga heavier gauge of metal sheet.

Other and 7 parent to those skilled in the art from the following dtailed description of theannexed sheet by; way of preferred exampleonly, bodiment of thepresent invention.

On the drawings:

Figure 1 is a perspective view of a substantially. flat metal blank asused in forming the turnbuckle barrel of the present; invention with aformed barrel shown, in dashed outline superimposed on the blank;

Figure 2 is a plan view of a turnbuckle barrel according to the presentinvention;

Figure 3 is a side elevational sectional view of the barrel shown inFigure 2',

Figure 4 is a side elevational'view of a turnbuckle according to thepresent invention with clamping rings thereon and connecting membersinserted in the end portions; and

Figure 5 is a reduced size and, elevational view-taken along l n Vi -T fFigure 4.

As shown on the drawings:

the turnbuckle 10 has a downwardly offset central section 11 of greaterwidth than end sections 12 thereof. Inclined flanges 11a connect thecentral portion or kerfs 13 are pressed angularly downwardly from themetal of the blank, two in each end section 12, the tabs lyingsubstantially along a single longitudinal line. The longitudinal sideedges of the end sections are recessed or indented along their length asat 14 and have inturned rounded outer ends 14a and outturned roundedinner ends 14b.

In Figures 2, 3, 4 and 5 is shown a turnbuckle barrel 15 which is formedby rolling the blank 10 of Figure 1 into tubular shape. The longitudinaledges of the central section 11 are abutted firmly together as bywelding 16. The central section 11 of the blank 10 forms a diametricallyenlarged central portion 17 of the barrel I 15. End portions 18 areformed by the end sections and have slots 19 therein formed by therecessed edges 14. Each slot has an outwardly flared rounded entrancemouth 19a formed by the ends 14a and a rounded botformed by the ends14b.

The ends 18 and central portion are joined by the sloping shoulders 17aformed from the flanges 11a. Retaining lugs 20, diametrically oppositeto the slots 19, are formed by the tabs 13 of the blank 10.

As best seen in Figures 2 and 3, the end portions 18 have internalthreads 21, the threads in one end portion being right hand and those inthe other end portion being left hand. The threads 21 are preferablyformed after the weld 16.

It should be noted that the inside diameter of the central portion 17 isgreater than the major diameter of the internal threads 21. Hence, theinner surface of the central portion 17 remains smooth and unnotched andconsequently is free from any points of unnecessary stressconcentration.

Referring to Figure 4, clamping rings 22 are disposed over the endportions 18 of the barrel 15 and are prevented from axial movementthereon by the lugs 20. The rings 22 have outturned clamping cars 23 ateither side of their longitudinal slots 24. Bolts 25 are insertedthrough holes in the ears and extend across the slots 24. Nuts 26 arethreadedly inserted onto the ends of bolts 25 and have lock washers 27thereunder.

Connecting members 28 and 29 having externally threaded portions 30 and31 respectively are threadedly metal blank inserted into the endportions 18 of the barrel 15 to eninsertion of a threading tool,resulting in further increa:

gage with the internal threads 21 formed therein. in case ofmanufacture. Easily formed lugs serve to It It is apparent from thestructure described that rotatain clamping rings on each end of thebarrel so that th tlon of the barrel 15 in one direction will serve tofurrings will be retained in proper axial position on the end therinsert both of the connecting members 28 and 29 of the barrel and willnot slip off the ends when loosene into the barrel thereby tighte ingthe connection. Conto allow insertion of the connecting members.

versely, rotation of the barrel in the opposite direc- It will beunderstood that modifications and variation tion will serve to loosenthe connection. When the demay be effected Without departing from thescope of th sired relationship between the connecting members 28 novelconcepts of the present invention.

and 29 has been achieved, the nuts 26 are tightened down 10 I claim asmy invention:

on the bolts thereby tightening the clamping rings 22 in a tubularclamping structure, a tube comprising 2 about the end portions 18. Thus,the walls of the end single curled sheet, of substantially uniformthickness portions 18 will be pressed firmly against the threaded havingits central portion of wider extent than the em sections 30 and 31,thereby effecting a tight, non-rotating portions thereof and depressedradially and cylindricall connection between the connecting members 28and 29. 15 outwardly with longitudinally juxta-opposed edges ex- Fromthe above description it will be understood that tending and ofi'setcircumferentially beyond the oppothe present invention provides animproved turnbuckle site and remaining end portions of the tube andjoined having a non-threaded, diametrically enlarged central togetherleaving gaps in the end portions longitudinally portion which serves toincrease the strength of the aligned with said joined edges, saiddepressed central barrel Without materially changing the conventional 0portion at each of its ends having an annular reinforcmethod of formingsuch turnbuckles and without increasing shoulder merging into theadjoining tube end portion ing the gauge of the metal used in formingthe barrel. adjacent the inner end of the associated gap in the end Itcan be readily seen that the turnbuckle barrel is eX- portion as Well asadjacent an end of the joined edges. peditiously (but not necessarily)manufactured by rolling a pregioluslyhformed sltibstafntially flatbliifilk intg tlhe 5 References Cited in the file of this patent propertu u ar s ape. W en ormed in suc a tu u ar shape internal threads areeasily cut in the ends of the UNITED STATES PATENTS barrel, and sincethe enlarged central portion has a Number Name Date larger insidediameter than the major diameter of the 339,534 Dickson Apr. 6, 1886threads, each of the threaded portions may be of mini- 0 390,992Stillman Oct. 9, 1888 mum length for proper engagement while stillallowing 935,659 Johnson Oct. 5, 1909 for proper adjustment within theunthreaded central por- 935,660 Johnson Oct. 5, 1909 tion. As a furtherresult of the increased diameter cen- 1,148,041 Minkler July 27, 1915tral portion, threading of the end portion may be easily 1,326,008Tarbox Dec. 23, 1919 accomplished without precise control over the depthof 2,526,470 Gauthier Oct. 17, 1950

